57 lines
1.6 KiB
C++
57 lines
1.6 KiB
C++
// placenew2.cpp -- new, placement new, no delete
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#include <iostream>
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#include <string>
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#include <new>
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using namespace std;
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const int BUF = 512;
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class JustTesting
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{
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private:
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string words;
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int number;
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public:
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JustTesting(const string & s = "Just Testing", int n = 0)
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{words = s; number = n; cout << words << " constructed\n"; }
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~JustTesting() { cout << words << " destroyed\n";}
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void Show() const { cout << words << ", " << number << endl;}
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};
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int main()
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{
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char * buffer = new char[BUF]; // get a block of memory
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JustTesting *pc1, *pc2;
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pc1 = new (buffer) JustTesting; // place object in buffer
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pc2 = new JustTesting("Heap1", 20); // place object on heap
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cout << "Memory block addresses:\n" << "buffer: "
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<< (void *) buffer << " heap: " << pc2 <<endl;
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cout << "Memory contents:\n";
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cout << pc1 << ": ";
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pc1->Show();
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cout << pc2 << ": ";
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pc2->Show();
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JustTesting *pc3, *pc4;
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// fix placement new location
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pc3 = new (buffer + sizeof (JustTesting))
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JustTesting("Better Idea", 6);
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pc4 = new JustTesting("Heap2", 10);
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cout << "Memory contents:\n";
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cout << pc3 << ": ";
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pc3->Show();
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cout << pc4 << ": ";
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pc4->Show();
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delete pc2; // free Heap1
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delete pc4; // free Heap2
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// explicitly destroy placement new objects
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pc3->~JustTesting(); // destroy object pointed to by pc3
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pc1->~JustTesting(); // destroy object pointed to by pc1
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delete [] buffer; // free buffer
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// std::cin.get();
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return 0;
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}
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